AccountEdge and 64 Bit
When running AccountEdge on High Sierra, MacOS 10.13 (or later) you may see a message about AccountEdge not being optimized for your Mac because it's a 32 bit application. As Apple says in the article linked to the message "Yes, you may continue to use 32-bit apps with your Mac today. Using 32-bit software has no adverse effects on your data or your computer.”
While AccountEdge is currently a 32 bit application, we have been hard at work on a 64 bit version.
Apple announced that the next version of MacOS (to be launched in 2018) will support 32 bit applications with potential compromise and that the following MacOS version (suspected launch date in 2019) will be 64-bit only. We fully expect AccountEdge to be compliant with all future MacOS releases and to be 64-bit in alignment with Apple’s timeline.
As with any new operating system, we recommend you don’t install the next version of MacOS until it is officially released (in other words, don't run beta versions/public preview releases) if AccountEdge is critical to your business. We will share our compatibility statement when we have fully tested AccountEdge against the new, production version of the OS.
You can read Apple's statement on the transition to 64 bit here in this article.